Brain morphometric changes in fibromyalgia and the impact of psychometric and clinical factors: a volumetric and diffusion-tensor imaging study

BACKGROUND

Previous studies have repeatedly found distinct brain morphometric changes in patients with fibromyalgia (FM), mainly affecting gray and white matter abnormalities in areas related to sensory and affective pain processing. However, few studies have thus far linked different types of structural changes and not much is known about behavioral and clinical determinants that might influence the emergence and progression of such changes.

METHODS

We used voxel-based morphometry (VBM) and diffusion-tensor imaging (DTI) to detect regional patterns of (micro)structural gray (GM) and white matter (WM) alterations in 23 patients with FM compared to 21 healthy controls (HC), while considering the influence of demographic, psychometric, and clinical variables (age, symptom severity, pain duration, heat pain threshold, depression scores).

RESULTS

VBM and DTI revealed striking patterns of brain morphometric changes in FM patients. Bilateral middle temporal gyrus (MTG), parahippocampal gyrus, left dorsal anterior cingulate cortex (dACC), right putamen, right caudate nucleus, and left dorsolateral prefrontal cortex (DLPFC) showed significantly decreased GM volumes. In contrast, increased GM volume was observed in bilateral cerebellum and left thalamus. Beyond that, patients displayed microstructural changes of WM connectivity within the medial lemniscus, corpus callosum, and tracts surrounding and connecting the thalamus. Sensory-discriminative aspects of pain (pain severity, pain thresholds) primarily showed negative correlations with GM within bilateral putamen, pallidum, right midcingulate cortex (MCC), and multiple thalamic substructures, whereas the chronicity of pain was negatively correlated with GM volumes within right insular cortex and left rolandic operculum. Affective-motivational aspects of pain (depressive mood, general activity) were related to GM and FA values within bilateral putamen and thalamus.

CONCLUSIONS

Our results suggest a variety of distinct structural brain changes in FM, particularly affecting areas involved in pain and emotion processing such as the thalamus, putamen, and insula.

Longitudinal association of sedentary time and physical activity with pain and quality of life in fibromyalgia

OBJECTIVE

To analyze changes over time and the predictive value of baseline and changes of sedentary time (ST) and physical activity (PA) on pain, disease impact, and health-related quality of life (HRQoL) at 2- and 5-year follow-up in women with fibromyalgia.

METHODS

This is a longitudinal and exploratory study with three time points. A total of 427 women with fibromyalgia (51.4 ± 7.6 years) were followed after 2 (n = 172) and 5 years (n = 185). ST and PA (light and moderate-to-vigorous [MVPA]) were assessed using triaxial accelerometers. Pain, disease impact, and HRQoL were measured using: pressure pain threshold, the pain subscale of the revised fibromyalgia impact questionnaire (FIQR), the bodily pain subscale of the 36-item short-form health survey (SF-36), a visual analog scale (VAS), the FIQR, and the SF-36 physical and mental components.

RESULTS

Over 5 years, pressure pain threshold, ST, light PA, and MVPA variables were worsened, while FIQR and SF-36 variables were improved (Cohen's d < 0.1-0.3). Baseline ST or light PA were not associated with future outcomes, whereas greater MVPA at baseline was associated with better SF-36 bodily pain at 5-year follow-up (β = 0.13). Reducing ST and increasing light PA were associated with better bodily pain (β = -0.16 and 0.17, respectively) and SF-36 physical component (β = -0.20 and 0.17, respectively) at 5-year follow-up. Increasing MVPA was associated with less pain (pressure pain threshold, VAS, and FIQR-pain) and better SF-36 physical component at 2- and 5-year follow-up (β's from -0.20 to 0.21).

CONCLUSIONS

Objectively measured variables slightly worsened over years, while for self-reported outcomes there was a trend for improvement. Reductions in ST and increases in light PA and MVPA were associated with better HRQoL at 5-year follow-up, and increases in MVPA were additionally associated with better pain and HRQoL at 2-year follow-up.

Severity of symptoms persists for decades in fibromyalgia-a 26-year follow-up study

The aim of this study is to find out the outcome of 28 patients who got the diagnosis of primary fibromyalgia (pFM) 26 years ago. In 1986, 56 patients with widespread pain were examined and filled in a base questionnaire (BQ). Of them, 42 fulfilled the Yunus criteria for pFM. Twenty-six years later, addresses of 38 patients were found, and an extensive follow-up questionnaire (FupQ) was mailed to them. Of them, 28 (74%) answered the FupQ. This included nine identical questions with the BQ and questions concerning changes in their symptoms and quality of life (Qol). Three patients (11%) had healed from fibromyalgia (FM), and 23% reported having one or several symptomless periods lasting at least 1 year. In others (n = 25), all but pain and ache showed slight deterioration. Despite the aging and FM, the level of functional ability evaluated by Stanford Health Assessment Questionnaire (HAQ) remained at the same level (BQ 0.41 vs. Fup 0.44, p = 0.82). The sum score of reported symptoms (n = 21) did not change significantly (10.8 (SD 2.9) vs. 11.1 (SD 4.1), p = 0.75). Experienced sleeplessness increased most significantly (27 vs. 65%, p = 0.0034). Exercising did not have a significant influence on the changes of the measured parameters. However, the three healed patients exercised regularly. Symptoms of FM have persisted in most patients for decades without significant deterioration of self-reported functional ability. About one fourth of patients had experienced long symptomless periods during their illness. Three patients (11%) reported that they have healed from FM.

Fibromyalgia Outcomes Over Time: Results from a Prospective Observational Study in the United States

Background:

Longitudinal research on outcomes of patients with fibromyalgia is limited.

Objective:

To assess clinician and patient-reported outcomes over time among fibromyalgia patients.

Methods:

At enrollment (Baseline) and follow-up (approximately 2 years later), consented patients were screened for chronic widespread pain (CWP), attended a physician site visit to determine fibromyalgia status, and completed an online questionnaire assessing pain, sleep, function, health status, productivity, medications, and healthcare resource use.

Results:

Seventy-six fibromyalgia patients participated at both time points (at Baseline: 86.8% white, 89.5% female, mean age 50.9 years, and mean duration of fibromyalgia 4.1 years). Mean number of tender points at each physician visit was 14.1 and 13.5, respectively; 11 patients no longer screened positive for CWP at follow-up. A majority reported medication use for pain (59.2% at Baseline, 62.0% at Follow-up). The most common medication classes were opioids (32.4%), SSRIs (16.9%), and tramadol (14.1%) at Follow-up. Significant mean changes over time were observed for fibromyalgia symptoms (modified American College of Rheumatology 2010 criteria: 18.4 to 16.9; P=0.004), pain interference with function (Brief Pain Inventory-Short Form: 5.9 to 5.3; P=0.013), and sleep (Medical Outcomes Study-Sleep Scale: 58.3 to 52.7; P=0.004). Patients achieving ≥2 point improvement in pain (14.5%) experienced greater changes in pain interference with function (6.8 to 3.4; P=0.001) and sleep (62.4 to 51.0; P=0.061).

Conclusion:

Fibromyalgia patients reported high levels of burden at both time points, with few significant changes observed over time. Outcomes were variable among patients over time and were better among those with greater pain improvement.

EpiFibro (Brazilian Fibromyalgia Registry): data on the ACR classification and diagnostic preliminary criteria fulfillment and the follow-up evaluation

INTRODUCTION

EpiFibro (Brazilian Epidemiological Study of Fibromyalgia) was created to study Fibromyalgia patients. Patients were included since 2011 according to the 1990 American College of Rheumatology Classification Criteria for Fibromyalgia (ACR1990).

OBJECTIVES

To determine how many patients still fulfill the ACR1990 and the ACR2010 criteria in 2014; to determine the correlation between the impact of FM and to describe data on the follow-up evaluation.

METHODS

This is a cross sectional study in a multicenter cohort of patients. The data was collected between 2013 and 2015. Physician included patients that fulfilled the ACR1990 criteria on the date of entry. The follow-up data were considered only for patients with at least two evaluations. A minimally significant change was considered to be a 30% variation of parameters scores.

RESULTS

810 patients' data were analyzed. Patients presented a mean age of 51.8±11.5 years old. There were 786 female. Most patients met both criteria. There was a greater fulfilling of the ACR2010. There was a moderate correlation between Polysymptomatic Distress Scale and Fibromyalgia Impact Questionnaire. Three hundred fourteen patients with more than one assessment were found, but 88 patients were excluded. Thus, 226 patients with one follow-up monitoring parameter were considered (Fibromyalgia Impact Questionnaire: 222; Polysymptomatic Distress Scale: 199; both: 195). The mean follow-up time was 9.1±7.5 months (1-44). Most patients became stable.

CONCLUSION

InEpiFibro, most patients fulfill simultaneously the ACR1990 and ACR2010. A larger number of patients fulfill the ACR2010 at the time of the evaluation. There was a moderate correlation between the Polysymptomatic Distress Scale and the Fibromyalgia Impact Questionnaire. Most patients remained stable over time.

Overlapping structural and functional brain changes in patients with long-term exposure to fibromyalgia pain

OBJECTIVE

There is vast evidence to support the presence of brain aberrations in patients with fibromyalgia (FM), and it is possible that central plasticity is critical for the transition from acute to chronic pain. The aim of the present study was to investigate the relationship between brain structure and function in patients with FM.

METHODS

Functional connectivity of the brain during application of intermittent pressure-pain stimuli and measures of brain structure were compared between 26 patients with FM and 13 age- and sex-matched healthy controls. Magnetic resonance imaging (MRI) was performed to obtain high-resolution anatomic images and functional MRI scans of the brain, which were used for measurements of pain-evoked brain activity.

RESULTS

FM patients displayed a distinct overlap between decreased cortical thickness, decreased brain volumes, and decreased functional regional coherence in the rostral anterior cingulate cortex. The morphometric changes were more pronounced with longer exposure to FM pain. In addition, there was evidence of an association between structural and functional changes in the mesolimbic areas of the brain and the severity of comorbid depression symptoms in FM patients.

CONCLUSION

The combined integration of structural and functional measures allowed for a unique characterization of the impact of FM pain on the brain. These data may lead to the identification of early structural and functional brain alterations in response to pain, which could be used to develop markers for predicting the development of FM and other pain disorders.

Patients with fibromyalgia display less functional connectivity in the brain's pain inhibitory network

BACKGROUND

There is evidence for augmented processing of pain and impaired endogenous pain inhibition in Fibromyalgia syndrome (FM). In order to fully understand the mechanisms involved in FM pathology, there is a need for closer investigation of endogenous pain modulation. In the present study, we compared the functional connectivity of the descending pain inhibitory network in age-matched FM patients and healthy controls (HC).We performed functional magnetic resonance imaging (fMRI) in 42 subjects; 14 healthy and 28 age-matched FM patients (2 patients per HC), during randomly presented, subjectively calibrated pressure pain stimuli. A seed-based functional connectivity analysis of brain activity was performed. The seed coordinates were based on the findings from our previous study, comparing the fMRI signal during calibrated pressure pain in FM and HC: the rostral anterior cingulate cortex (rACC) and thalamus.

RESULTS

FM patients required significantly less pressure (kPa) to reach calibrated pain at 50 mm on a 0-100 visual analogue scale (p < .001, two-tailed). During fMRI scanning, the rACC displayed significantly higher connectivity to the amygdala, hippocampus, and brainstem in healthy controls, compared to FM patients. There were no regions where FM patients showed higher rACC connectivity. Thalamus showed significantly higher connectivity to the orbitofrontal cortex in healthy controls but no regions showed higher thalamic connectivity in FM patients.

CONCLUSION

Patients with FM displayed less connectivity within the brain's pain inhibitory network during calibrated pressure pain, compared to healthy controls. The present study provides brain-imaging evidence on how brain regions involved in homeostatic control of pain are less connected in FM patients. It is possible that the dysfunction of the descending pain modulatory network plays an important role in maintenance of FM pain and our results may translate into clinical implications by using the functional connectivity of the pain modulatory network as an objective measure of pain dysregulation.

The longitudinal outcome of fibromyalgia: a study of 1555 patients

OBJECTIVE

To describe the diagnosis status and outcome of patients diagnosed with fibromyalgia (FM) by US rheumatologists.

METHODS

We assessed 1555 patients with FM with detailed outcome questionnaires during 11,006 semiannual observations for up to 11 years. At entry, all patients satisfied American College of Rheumatology preliminary 2010 FM criteria modified for survey research. We determined diagnosis status, rates of improvement, responder subgroups, and standardized mean differences (effect sizes) between start and study completion scores of global well-being, pain, sleep problems, and health related quality of life. (QOL) RESULTS: The 5-year improvement rates were pain 0.4 (95% CI 0.2, 0.5), fatigue 0.4 (95% CI 0.2, 0.05), and global 0.0 (95% CI -0.1, 0.1). The standardized mean differences were patient global 0.03 (95% CI -0.02, 0.08), pain 0.22 (95% CI 0.16, 0.28), sleep problems 0.20 (95% CI 0.14, 0.25), physical component summary of the Short-form 36 (SF-36) 0.11 (95% CI -0.14, -0.07), and SF-36 mental component summary 0.03 (95% CI -0.07, 0.02). Patients switched between criteria-positive and criteria-negative states, with 716 patients (44.0%) failing to meet criteria at least once during 4228.5 patient-years (7448 observations). About 10% of patients had substantial improvement and about 15% had moderate improvement of pain. Overall, FM severity worsened in 35.9% and pain in 38.6%.

CONCLUSION

Although we found no average clinically meaningful improvement in symptom severity overall, 25% had at least moderate improvement of pain over time. The result that emerged from this longitudinal study was one of generally continuing high levels of self-reported symptoms and distress for most patients, but a slight trend toward improvement.

Employment and health status changes among women with fibromyalgia: a five-year study

OBJECTIVE

To assess changes in health status of women with fibromyalgia (FM) over 5 years and determine whether baseline employment status influences health outcomes adjusting for other baseline factors.

METHODS

Two hundred eighty-seven women with FM were recruited from a national sample of rheumatologists and interviewed by phone at baseline and annually for 4 years. Data were collected on pain, fatigue, Center for Epidemiologic Studies Depression Scale and Modified Health Assessment Questionnaire (M-HAQ) scores, demographic characteristics, and employment status. At the end of the study, 211 participants remained. Data were analyzed using multilevel modeling techniques. Bootstrap methods adjusted for the cluster sampling.

RESULTS

The participants' mean +/- SD age was 47 +/- 11 years, their mean +/- SD education level was 14 +/- 2 years, 90% were white, 50% employed, 64% married, and their median household income was >or=$50,000. Mean +/- SD scores at baseline were 57.2 +/- 24 for pain, 75.4 +/- 22 for fatigue, 22.9 +/- 13 for depression, and 0.73 +/- 0.5 for the M-HAQ. Multilevel modeling indicated that all health status measures declined significantly over time except for pain. Rates of change varied from -1.22 for fatigue to -0.03 for the M-HAQ. Except for pain, patients who were employed at baseline had better health status over time. The employment and time interaction was not significant, indicating that health status changed at the same rate regardless of employment status. Other significant factors were age and income.

CONCLUSION

Employed women with FM have better health status at baseline and maintain that advantage over time. Employment does not seem to provide a protective health benefit.

[Definition, classification and diagnosis of fibromyalgia syndrome]

BACKGROUND

Interdisciplinary guidelines for the definition, classification and diagnosis of chronic widespread pain (CWP) and fibromyalgia syndrome (FMS) were developed by collaboration of 10 German medical and psychological associations and 2 patient self-help organizations.

METHODS

A systematic literature search was performed in the Cochrane Library (1993-12/2006), Medline (1980-2006), PsychInfo (1966-12/2006), and Scopus (1980-12/2006). Levels of evidence were assigned according to the classification system of the Oxford Centre for Evidence-Based Medicine. Grading of the strength of recommendation was done according to the German program for disease management guidelines. Standardized procedures to reach a consensus on recommendations were used.

RESULTS

CWP is defined by the criteria of the American College of Rheumatology (ACR--strong consensus). FMS can be diagnosed for clinical purposes by symptom-based criteria (without tender point examination) as well as by the ACR criteria (strong consensus).

Is there a predisposition for the development of autoimmune diseases in patients with fibromyalgia? Retrospective analysis with long term follow-up

The objectives of the study were to evaluate the prevalence of antinuclear antibodies (ANA) in patients with fibromyalgia (FM) and the probability of the development of clinically overt connective tissue diseases. Four hundred and fifty FM patients were compared to 129 healthy matched blood donors. ANA testing was performed by immunofluorescence on rat tissue sections; in case of highly positive results, ANA were specified further by ELISA and immunodiffusion. All ANA positive FM patients were invited for a control examination. The ANA negative patients received a questionnaire, which was designed to identify those patients with possible connective tissue diseases (CTD). There was no significant difference in the frequency of ANA or thyroid antibodies between patients and controls (11.6% vs. 7%). Two patients had developed SLE: one was already ANA/anti-dsDNA positive at time of first diagnosis of FM; in the other, specific antibodies and SLE-related symptoms developed after 4.5 years. The probability for FM patients to develop CTD (SLE) within one year is 0.0027%, which is comparable to the incidence of SLE in the general population (0.005%). The risk of CTD is not increased in FM. The detection of ANA does not predict the development of CTD. However, in individual cases, FM may be an early sign of an autoimmune disease.

Pathophysiological mechanisms in chronic musculoskeletal pain (fibromyalgia): the role of central and peripheral sensitization and pain disinhibition

Chronic musculoskeletal pain has biological, psychological and social components. This review deals with the biological factors, with emphasis on the fibromyalgia syndrome (FMS). Studies on central sensitization of pain-transmitting neurons, changes in endogenous pain modulation that give rise to pain disinhibition, referred pain, pain-related decrease in muscle strength and endurance, and pain generators in deep tissues are reviewed. In FMS there is strong scientific support for the statement that the biological part of the syndrome is a longstanding or permanent change in the function of the nociceptive nervous system that can be equated with a disease. Further research is necessary in order to determine which methods are best for diagnosis of the pain hypersensitivity in clinical practice. FMS may be the far end of a continuum that starts with chronic localized/regional musculoskeletal pain and ends with widespread chronic disabling pain.

A Critical Analysis of the Tender Points in Fibromyalgia

OBJECTIVE

To pilot methodologies designed to critically assess the American College of Rheumatology's (ACR) diagnostic criteria for fibromyalgia.

DESIGN

Prospective, psychophysical testing.

SETTING

An urban teaching hospital.

SUBJECTS

Twenty-five patients with fibromyalgia and 31 healthy controls (convenience sample).

INTERVENTIONS

Pressure pain threshold was determined at the 18 ACR tender points and five sham points using an algometer (dolorimeter).

OUTCOME MEASURES

The patients "algometric total scores" (sums of the patients' average pain thresholds at the 18 tender points) were derived, as well as pain thresholds across sham points.

RESULTS

The "algometric total score" could differentiate patients with fibromyalgia from normals with an accuracy of 85.7% (P < 0.001). Even a single tender point had a diagnostic accuracy between 75% and 89%. Although fibromyalgics had less pain across sham points than across ACR tender points, sham points also could be used for diagnosis (85.7%; Ps < 0.001). Hierarchical cluster analysis showed that three points could be used for a classification accuracy equivalent to the use of all 18 points.

CONCLUSIONS

There was a significant difference in the "algometric total score" between patients with fibromyalgia and controls, and we suggest this quantified (although subjective) approach may represent a significant improvement over the current diagnostic scheme, but this must be tested vs other painful conditions. The points specified by the ACR were only modestly superior to sham points in making the diagnosis. Most importantly, this pilot suggests single points, smaller groups of points, or sham points may be as effective in diagnosing fibromyalgia as the use of all 18 points, and suggests methodologies to definitively test that hypothesis.

Long-term effects of a shared decision-making intervention on physician-patient interaction and outcome in fibromyalgia. A qualitative and quantitative 1 year follow-up of a randomized controlled trial

OBJECTIVE

Fibromyalgia syndrome (FMS) patients and their doctors frequently complain on interaction difficulties. We investigated the effects of a shared decision-making (SDM) intervention on physician-patient interaction and health outcome.

METHODS

Sixty-seven FMS patients of an outpatient university setting that had been included in a randomized controlled trial were followed up. They were either treated in an SDM group or in an information group. Both groups saw a computer based information tool on FMS, but only the SDM group was treated by doctors which underwent a special SDM communication training. A comparison group of 44 FMS patients receiving treatment as usual was recruited in rheumatological practices. We assessed patients and their doctors using a combined qualitative and quantitative approach. Patients and doctors were followed-up after 3 months (T2) and after 1 year (T3).

RESULTS

The significantly best quality of physician-patient interaction was reported by patients and doctors of the SDM group, followed by the information group. Coping had more often improved in the SDM group than in the information group. However directly health related outcome variables had not improved in any of the groups at T3.

CONCLUSION

An SDM intervention can lead to an improved physician-patient relationship from the patients' and from the doctors' perspective.

PRACTICE IMPLICATIONS

It should be considered to include SDM in standard care for FMS patients.

Are patients with systemic lupus erythematosus at increased risk for Fibromyalgia?

Widespread chronic pain, fatigue, and distress do not represent risk factors for future systemic lupus erythematosus (SLE) or other autoimmune syndromes. On the other hand, SLE seems to be a significant risk factor for fibromyalgia (FM). Up to 47% of SLE patients fulfill FM criteria. SLE patients with concomitant FM are often highly symptomatic and dysfunctional. The presence of FM symptoms in SLE patients, however, does not predict more extensive organ involvement or lupus activity. The high concordance of SLE with FM suggests common mechanisms related to pain and distress in both patient groups. Recent research suggests involvement of N-methyl-D-aspartate (NMDA) and neurokinin receptor systems. Thus, autoimmune activity against these receptor systems in SLE patients could result in pain, cognitive defects, and chronic pain states including FM. Conversely, treatment of SLE-FM patients with inhibitors of NMDA or neurokinin receptors may prevent or alleviate cognitive abnormalities and chronic pain, as well as FM.

Validity and reliability testing of the Quality of Life Scale, Swedish version in women with fibromyalgia - statistical analyses

One consequence of constant widespread pain is a low quality of life. The purpose of the study was to examine whether the Quality of Life Scale, Swedish version (QOLS-S), regarded as a generic quality-of-life instrument, is a reliable and valid instrument for use in women with fibromyalgia (FM). Women with FM (n = 113) contributed data on the QOLS-S and other standardized instrument at three points in time. Internal consistency reliability estimates ranged from 0.89 to 0.92. Convergent construct validity was indicated by moderate agreement with a global life satisfaction question. Discriminant construct validity was denoted by low correlations with the physical functioning subscale of the SF-36. In a factor analysis three factors emerged: 'personal and social well-being', 'relations with others' and 'active participation'. A few of the items have high cross-loadings, and the instrument could be improved by rewording those items to more closely reflect one specific factor. Overall, these results provide evidence that the QOLS-S has acceptable validity and reliability for use in women with FM.

Factors of importance for work disability in women with fibromyalgia: an interview study

OBJECTIVE

Fibromyalgia symptoms such as continuous pain, tiredness, hyperalgesia, and allodynia limit gainful employment. The present study examines which factors influence the decision to remain in a work role for women with fibromyalgia. This information is important for the individual and for public finances.

METHODS

Qualitative interviews were performed with 39 women, 19 of whom were gainfully employed and 20 who had stopped working. The transcribed interviews were analyzed and divided into categories and subcategories.

RESULTS

Four categories appear, at societal and individual levels, that were regarded as important by the women for remaining in a work role.

CONCLUSIONS

The ability to remain at work depends not only on limitations in work capacity, but also on the capacity of society to adjust work environments and work tasks. More individual solutions are needed to allow women with fibromyalgia to maintain work roles.

Management of fibromyalgia: what are the best treatment choices?

Fibromyalgia still represents an enigma to modern medicine and the aetiopathogenesis is far from explored. The management of patients with fibromyalgia is thus mostly based on empirical research, and only a few controlled studies have been performed. Basic drug therapy rests on the administration of amitriptyline and conventional analgesics. Such therapy should be initiated only after careful patient information and delineation of therapeutic goals are provided. Any drug therapy should be administered in combination with physical treatment and cognitive behavioural therapy. Because of the appearing contours of pathogenic mechanisms, hopefully a number of new drugs will be available to the patients with this complex pain syndrome in the near future.

Health status and disease severity in fibromyalgia: results of a six-center longitudinal study

OBJECTIVE

To determine the intermediate and long-term outcomes of fibromyalgia in patients seen in rheumatology centers in which there is special interest in the syndrome.

METHODS

We conducted a longitudinal outcome study by mailed comprehensive Health Assessment Questionnaire administered every 6 months to 538 patients, from 6 rheumatology centers, whose median duration of disease at first assessment was 7.8 years. The final assessment took place after 7 years. In addition, there was study followup on 85 patients who had attended the Wichita center for > 10 years.

RESULTS

Although functional disability worsened slightly and health satisfaction improved slightly, measures of pain, global severity, fatigue, sleep disturbance, anxiety, depression, and health status were markedly abnormal at study initiation and were essentially unchanged over the study period. Correlations between first and last assessment values were as high as r = 0.82. For some variables, abnormalities were 3 times greater at one center compared with another.

CONCLUSION

Patients with established fibromyalgia, seen in rheumatology centers in which there a special interest in the disease and followed up for as long as 7 years, have markedly abnormal scores for pain, functional disability, fatigue, sleep disturbance, and psychological status, and these values do not change substantially over time. Half the patients are dissatisfied with their health, and 59% rate their health as fair or poor. There are marked differences in disease severity among the various centers, but < 14% of the variance in outcomes can be explained by demographic or center factors. Values at the first assessment are predictive of final values.

Effects of experimental muscle pain on muscle activity and co-ordination during static and dynamic motor function

The relation between muscle pain, muscle activity, and muscle co-ordination is still controversial. The present human study investigates the influence of experimental muscle pain on resting, static, and dynamic muscle activity. In the resting and static experiments, the electromyography (EMG) activity and the contraction force of m. tibialis anterior were assessed before and after injection of 0.5 ml hypertonic saline (5%) into the same muscle. In the dynamic experiment, injections of 0.5 ml hypertonic saline (5%) were performed into either m. tibialis anterior (TA) or m. gastrocnemius (GA) and the muscle activity and co-ordination were investigated during gait on a treadmill by EMG recordings from m. TA and m. GA. At rest no evidence of EMG hyperactivity was found during muscle pain. The maximal voluntary contraction (MVC) during muscle pain was significantly lower than the control condition (P < 0.05). During a static contraction at 80% of the pre-pain MVC muscle pain caused a significant reduction in endurance time (P < 0.043). During dynamic contractions, muscle pain resulted in a significant decrease of the EMG activity in the muscle, agonistic to the painful muscle (P < 0.05), and a significant increase of the EMG activity of the muscle, antagonistic to the painful muscle (P < 0.05). Muscle pain seems to cause a general protection of painful muscles during both static and dynamic contractions. The increased EMG activity of the muscle antagonistic to the painful muscle is probably a functional adaptation of muscle co-ordination in order to limit movements. Modulation of muscle activity by muscle pain could be controlled via inhibition of muscles agonistic to the movement and/or excitation of muscles antagonistic to the movement. The present results are in accordance with the pain-adaptation model (Lund, J.P., Stohler, C.S. and Widmer, C.G. In: H. Vaerøy and H. Merskey (Eds.), Progress in Fibromyalgia and Myofascial Pain. Elsevier, Amsterdam, 1993, pp. 311-327.) which predicts increased activity of antagonistic muscle and decreased activity of agonistic muscle during experimental and clinical muscle pain.

Mutations in the c-erbA beta 1 gene: do they underlie euthyroid fibromyalgia?

Fibromyalgia, a chronic condition of widespread pain, stiffness, and fatigue, has proven unresponsive to drugs, the use of which is based on the 'serotonin-deficiency hypothesis'. An alternative hypothesis-failed transcription regulation by thyroid hormone-can explain the serotonin deficiency and other objective findings and symptoms of euthyroid fibromyalgia. Virtually every feature of fibromyalgia corresponds to signs or symptoms associated with failed transcription regulation by thyroid hormone. In hypothyroid fibromyalgia, failed transcription regulation would result from thyroid-hormone deficiency. In euthyroid fibromyalgia, failed transcription regulation may result from low-affinity thyroid hormone receptors coded by a mutated c-erbA beta 1 gene, yielding partial peripheral resistance to thyroid hormone. The hypothesis of this paper is that, in euthyroid fibromyalgia, a mutant c-erbA beta 1 gene (or alternately, the c-erbA alpha 1 gene) results in low-affinity thyroid-hormone receptors that prevent normal thyroid hormone regulation of transcription. As in hypothyroidism, this would cause a shift toward alpha-adrenergic dominance and increases in both cyclic adenosine 3'-5'-phosphate phosphodiesterase and inhibitory Gi proteins. The result would be tissue-specific hypothyroid-like symptoms despite normal circulating thyroid-hormone levels.

Fibromyalgia outcome: the predictive values of symptom duration, physical activity, disability pension, and critical life events--a 4.5 year prospective study

Forty-four fibromyalgia patients were followed through 4.5 years to assess the extent to which symptom duration, physical activity level, disability pensions, and the occurrence of critical life events would predict long-term outcome. Outcome measures included pressure tenderness (dolorimeter score), work capacity (ergometer cycle test), global subjective improvement (verbal rating scale), and visual analogue scale ratings of pain, disturbed sleep, lack of energy, and depression. Significant outcome predictors were identified by means of separate multiple regression analyses on each outcome measure at follow-up, using symptom duration, physical activity level, disability pension status, and occurrence of critical life events as independent variables, together with baseline symptom intensity and age, which were adjusted for. An adequate physical activity level and increasing age predicted a positive outcome, while receiving a permanent disability pension or having experienced an excess of major negative life events predicted a negative outcome. Symptom duration did not affect outcome.

Impact of fibromyalgia on everyday life: a study of women in the USA and Sweden

The study investigated how 39 women with fibromyalgia (FM), living in two countries (USA or Sweden), report the consequences of fibromyalgia on everyday life activities. Data were collected using questionnaires, diaries and interviews. The result showed that the impact on everyday life was considerable. The majority of the women experienced pain and fatigue for more than 90% of their time awake. There were no significant differences between the national groups in time use, problems with everyday activities, or quality of life. Overall, the differences between individuals were greater than between the national groups. The majority of the employed patients in the Swedish group had reduced their working time, while the employed patients in the USA group worked mainly full-time. Patients who were able to reduce their working hours to fit their perceived capacity were less exhausted during their leisure, and reported higher satisfaction with daily activities.

Chronic regional muscular pain in women with precise manipulation work. A study of pain characteristics, muscle function, and impact on daily activities

Pain characteristics, muscle function and impact on daily activities were studied in 39 women with chronic regional muscular pain (RMP). They were all blue-collar workers in work involving precise manipulations. The main location of the pain was in the neck-shoulder region. Nineteen age-matched women with fibromyalgia (FM) were studied in the same way as the RMP patients. Thirty-seven women with no pain and with the same age and weight as the RMP patients served as reference group with respect to muscle strength and endurance. A follow-up study was done with respect to pain distribution and other pain characteristics 20 months after the initial examination. The findings were of the same nature in the RMP and the FM groups. The intensity of pain, the lowering of pain threshold for pressure, and the degree of sleep disturbance were greater in the FM than in the RMP group. Isometric muscle strength and static muscular endurance were reduced in both FM and RMP compared to reference values. The reduction in strength and endurance was greater in FM than in RMP. Even if the impact on everyday activities were greater in FM than in RMP, the impact was substantial in RMP patients also, for example with regard to work capacity. There were no transitions from RMP to FM during the 20 months to follow-up. Three FM patients, however, did not meet the ACR criteria for FM at follow-up.

Living with continuous muscular pain--patient perspectives. Part I: Encounters and consequences

The purpose of the present study was to focus on the patient perspectives of living with chronic muscular pain, and to identify factors that can explain and give further understanding of how the condition influences everyday life. Forty women with fibromyalgia, living in two different cultural, health care and social security settings, Sweden and the USA, were interviewed, using a semi-structured format. Three preliminary typologies are suggested for further studies: Encounters, Consequences, and Strategies. The study is presented in two articles: Part I: Encounters and consequences, Part II: Strategies for daily life. This first article shows that the contradiction between the patients' perception of illness and the lack of objective findings is stressful. The women feel rejected, misunderstood, and disbelieved, which prevents them from dealing with their situation constructively. Long investigation periods provoke anxiety, and confirmation of the diagnosis is a relief. Daily routines are disrupted, conflicts between life roles lead to additional stress and the women experience loss of ability to perform valued activities, lack of physical fitness and loss of future opportunities. Patients need early and adequate information and the consequences of the condition must be acknowledged and taken into consideration if secondary economic and psychosocial consequences are to be minimized.

Living with continuous muscular pain--patient perspectives. Part II: Strategies for daily life

This second article of the study Living with Continuous Muscular Pain is Part II: Strategies for Daily Life. The primary purpose was to explore, analyse and describe how women with fibromyalgia, living in two different cultural, health care and social security settings, managed their everyday life in spite of the limitations imposed by the condition. Data were collected through qualitative semi-structured interviews with 40 women, 20 living in the USA and 20 in Sweden. The different strategies used by the women were identified and a preliminary typology of strategies is proposed as a base for further and more specific studies. The results support earlier findings, though the qualitative approach adds knowledge regarding the women's own perception, interpretation and experiences of how to deal with the problems that arose. The findings in the two national groups were very similar, but differences in the medico-legal compensation systems influenced the women's opportunities to reduce working hours. Changes of habits, roles and lifestyle, as well as ergonomic considerations were required. These changes take time and require continued support from the environment and the health care providers. Further insight into the consequences of the condition is necessary for the planning of successful treatment and support programs.

Pain analysis in patients with fibromyalgia. Effects of intravenous morphine, lidocaine, and ketamine

Pain intensity, muscle strength, static muscle endurance, pressure pain threshold, and pain tolerance at tender points and control points were assessed in 31 patients with fibromyalgia (FM), before and after intravenous administration of morphine (9 patients), lidocaine (11 patients), and ketamine (11 patients). The three different studies were double-blind and placebo-controlled. The patients were classified as placebo-responders, responders (decrease in pain intensity by > 50%) and non-responders. The morphine test did not show any significant changes. The lidocaine test showed a pain decrease during and after the infusion. The ketamine test showed a significant reduction in pain intensity during and after the test period. Tenderness at tender points decreased and endurance increased significantly, while muscle strength remained unchanged. The present results support the hypothesis that the NMDA receptors are involved in pain mechanisms in fibromyalgia. These findings also suggest that central sensitization is present in FM and that tender points represent secondary hyperalgesia.

Chronic muscular pain: aetiology and pathogenesis

The conclusion is that no one single mechanism can explain FMS and is thus in that sense a compromise. FMS in some patients may start in the muscle, in other patients in the brain. The combination of peripheral and central factors is the key to the pathogenesis of FMS as long as FMS is defined as a pain syndrome.